Nandini Venkat Iyer; Jayant A Kher; Shekhar D Bhame
Abstract
The present study features the synthesis of Dodecylbenzene sulphonic acid-doped polypyrrole tungsten oxide (PPy-WO3) nanocomposites and its photocatalyic studies on Methylene Blue (MB). The nanocomposites of PPy with a very low concentration of WO3 were prepared using 0.05 to 0.3 wt.%, of WO3 nanoparticles. ...
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The present study features the synthesis of Dodecylbenzene sulphonic acid-doped polypyrrole tungsten oxide (PPy-WO3) nanocomposites and its photocatalyic studies on Methylene Blue (MB). The nanocomposites of PPy with a very low concentration of WO3 were prepared using 0.05 to 0.3 wt.%, of WO3 nanoparticles. The composites were characterized by using-ray Diffraction, FTIR and FESEM for phase identification, morphological studies. The electrical conduction of the nanostructured materials at room temperature exceeded that of PPy, with the electrical conductivity increasing linearly with higher WO3 concentrations. The band gap for the nanocomposite was found to be 2.12eV. The PL spectra substantiated the adequate segregation of charge carriers photoexcited in the samples. The nanocomposites were tested as photocatalysts for the degradation of methylene blue dye (MB). A two-step mechanism has been propsed for dye removal: adsorption (in the absence of UV light) and photodegradation on the photocatalyst surface (in the presence of UV light). The maximum removal efficiency for methylene blue dye was 98.31% in UV light for 0.16 g/L of the 0.3 wt.% PPy- WO3 nanocomposite, with a dye concentration of 5 mg/L. The addition of p-benzoquinone (*O2- scavenger) contributed to a significant decrease in the photodegradation efficiency of the catalyst, i.e.,63.21%, and thus can be believed as the main active species for the degradation of the methylene blue dye.
Shobha Musmade; Dinesh Punja Hase; Amit S Waghmare; Kailas R Kadam; Jayshree Khedkar; Anil G Gadhave; Kanhaiyalal S Bhavsar; Vaishali Dattatray Murade
Abstract
In the present work, truncated octahedron and octahedron shaped Cu2O and Cu2O/TiO2-QD composite have been synthesized using precipitation method and used as a photocatalyst. Synthesized material was characterized by using various analytical techniques- XRD, SEM, TEM and UV-Visible DRS. TEM images clearly ...
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In the present work, truncated octahedron and octahedron shaped Cu2O and Cu2O/TiO2-QD composite have been synthesized using precipitation method and used as a photocatalyst. Synthesized material was characterized by using various analytical techniques- XRD, SEM, TEM and UV-Visible DRS. TEM images clearly shows that the TiO2 was highly dispersed and firmly anchored on single crystals of copper oxide in Cu2O/TiO2-QD composite and also confirmed the truncated octahedron and octahedron shapes of copper oxide. The excellent performance of synthesized Cu2O/TiO2-QD photocatalyst has been proved the maximum degradation (89.00%) of Congo red dye at pH=6. The effect of various parameters in the dye degradation such as influence of pH, amount of photocatalyst, concentration of dye and reusability of the photocatalyst has been studied. The highest degradation rate was found with concentration of Congo red dye 9 mg/L, 150mg/L of Cu2O/TiO2-QD, and 110 min. Thus, the photocatalytic performance of Cu2O/TiO2-QD composite revealed the excellent and effective degradation of Congo-red dye.
Sarathi R; Sheeba N. L.; Selva Esakki E; Renuga Devi L; Meenakshi Sundar S
Abstract
Water pollution by organic pollutants is an ever increasing problem for the global concern. The present study is aimed at synthesizing Titanium di oxide nanoparticles under two different concentrations of Zinc as dopant material. The synthesized nanoparticles are used as a catalyst in degrading malachite ...
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Water pollution by organic pollutants is an ever increasing problem for the global concern. The present study is aimed at synthesizing Titanium di oxide nanoparticles under two different concentrations of Zinc as dopant material. The synthesized nanoparticles are used as a catalyst in degrading malachite green dye an organic pollutant. The morphological studies of zinc doped Titanium di Oxide nanoparticles were carried out using different spectroscopic and microscopic tools. From the XRD Spectra average crystallite size, lattice parameters, volume of unit cell are studied. The bandgap of the material was found by using UV-Vis absorbance Spectroscopy. Fourier Transform Infrared Spectroscopy confirms the functional group present in the sample. Under light illumination, metal oxide nanoparticles act as a good photocatalyst in converting a harmful material into a less harmful one. In this aspect the malachite green dye prepared from river water is degraded under the illumination of visible light. Almost above 95% of degradation in 60 min is observed reporting the Zinc doped Titanium dioxide as an eminent photocatalyst.
Marjan Tanzifi; Mohsen Jahanshahi; Majid Peyravi; Soodabeh Khalili
Abstract
Dye-containing wastewater is a major pollutant that can irreversibly damage the environment. Ultrafiltration membrane technology combined with photocatalysis is used for treatment of dye-containing solutions. To remove dye pollution, Methylene blue (MB) and Congo red (CR), graphitic carbon nitride (CNG) ...
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Dye-containing wastewater is a major pollutant that can irreversibly damage the environment. Ultrafiltration membrane technology combined with photocatalysis is used for treatment of dye-containing solutions. To remove dye pollution, Methylene blue (MB) and Congo red (CR), graphitic carbon nitride (CNG) and its zirconium dioxide nanocomposite (CNGZ) were used in the photocatalytic dynamic membrane system in both self-forming and pre-coated modes under household LED light. The filtration results of the self-forming membrane showed that the pure CNG- and nanocomposite-based photocatalytic membrane systems were more efficient for MB and CR dyes removal than the photocatalytic system in batch mode. In addition to improving dye molecule removal efficiency, adding the photocatalyst to the PES membrane also significantly increased water flux. Moreover, the respective MB and CR rejection rates were 29% and 47% for the pure PES membrane and 89% in 120 min and 100% in 80 min for the CNGZ-based photocatalytic membrane. This suggests that the photocatalytic membrane system is a more effective dye pollution remover than the pure PES. For comparison, the pre-coated dynamic membrane system used for MB dye removal was good for removing 98.6% within 20 min. The results suggest that CNGZ-based photocatalytic dynamic membrane is a promising technology for increasing dye molecules removal efficiency and flux in remediation of dye-containing wastewater.
Karthiga Rajendaran; Karthikarani Saravanan
Abstract
The green fabricated photocatalyst is promising material and could be applied for waste-water remediation and other ecological applications.Hibiscus floral extract surface modified Ni doped ZnO (HFNZO) was obtained by simple co-precipitation. The flowers have secondary metabolites such as phenolic compounds ...
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The green fabricated photocatalyst is promising material and could be applied for waste-water remediation and other ecological applications.Hibiscus floral extract surface modified Ni doped ZnO (HFNZO) was obtained by simple co-precipitation. The flowers have secondary metabolites such as phenolic compounds named as flavonoids; tannins are turned to be the reluctant to synthesize Ni/ZNO nanoparticles from the precursor. The prepared nanoparticles were examined by various characterization for their optical, structural and surface morphology properties was determined using Uv-Drs, FTIR, XRD, SEM, TEM, EDX, and XPStechniques. Absorption spectral shift of visible light region (red shift) and band gap reduction for ZnO (ZO), hibiscus modified ZnO (HFZO) and hibiscus surface modified Ni doped ZnO (HFNZO) properties were studied and shows a reduction in band gap of the nanoparticles from 3.0eV – 1.65 eV. Results obtained from XRD analysis shows that the synthesized HFNZO nanoparticles has a particle size of about 24.85 nm which is also confirmed by TEM analysis. A 98% visible-light-mediated degradation of the aqueous Rose aniline hydrochloride (RA) of 20 µM solution containing HFNZO of 0.05 g/L nanoparticles has achieved within 90 min. It follows pseudo first order Kinetic and the mechanism of generation of hydroxyl group due to flower extract surface modification and doping has been explained.
Nandini V Iyer; Ganesh Agawane; Abhishjek Bhapkar; Jayant Kher; Shekhar Bhame
Abstract
In this paper, we report, the synthesis of conducting polymer nanocomposites of nickel oxide polypyrrole (NiO-PPy) doped with dodecyl benzene sulphonic acid for its application as a photocatalyst. In-situ polymerization of the pyrrole technique was employed along with oxidant ammonium persulphate and ...
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In this paper, we report, the synthesis of conducting polymer nanocomposites of nickel oxide polypyrrole (NiO-PPy) doped with dodecyl benzene sulphonic acid for its application as a photocatalyst. In-situ polymerization of the pyrrole technique was employed along with oxidant ammonium persulphate and dodecyl benzene sulphonic acid as a dopant. The nanostructures were synthesized at different concentrations of NiO nanoparticles viz. 0.05 wt.%, 0.1 wt.%, 0.2 wt.% and 0.3 wt.%. The development of nanostructures was explored by Fourier Transform Infrared Spectrophotometer, Field Emission Scanning Electron Microscope, X-ray diffraction spectrometer, and electrical conductivity measurements. FTIR studies revealed a shift in the absorption band when pure PPy and NiO-PPy nanocomposites were studied, exhibiting the substantial interaction between the PPy network and the NiO. FE-SEM analysis demonstrated the consistent distribution of NiO with globular-shaped metal oxide materials in the PPy host template. The XRD studies for pure PPy revealed its amorphous nature while nanocomposites indicated the prominent NiO peaks arising from (111), (200) and (220) planes. The nanocomposites' direct electrical conductivity at room temperature was much higher than pure PPy. It was observed that the electrical conductivity for pure PPy was 0.409×10-5 S/cm while it substantially increased to 4.2×10-5 (S/cm) for 0.3% nanocomposite. The electrical studies revealed that the electrical conductivity goes on increasing with increased NiO concentration and then after a saturation point more PPy encapsulates the NiO and in turn reduces the electrical conductivity. With 50 mg of 0.3% nanocomposite, the photocatalytic degradation of the Methylene-Blue dye was 84.98%.
Jeba R; Radhika S; Padma C M; Ascar Davix X
Abstract
Pure and copper-doped Zirconium oxide nanoparticles were synthesized using a co-precipitation process and investigated the effect of doping on photocatalytic and anti-microbial activities. The prepared samples are pure tetragonal phase, as shown by the X-ray diffraction pattern, and the crystallite size ...
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Pure and copper-doped Zirconium oxide nanoparticles were synthesized using a co-precipitation process and investigated the effect of doping on photocatalytic and anti-microbial activities. The prepared samples are pure tetragonal phase, as shown by the X-ray diffraction pattern, and the crystallite size decreases as the dopant concentration increases. Higher dopant concentrations resulted in needle-shaped morphology, as seen in the SEM image. The presence of Zr, Cu, and O in the sample is confirmed by EDS analysis. According to UV-VIS analysis, when the Cu content is increased, a more significant wavelength absorption band edge is formed, and the band gap reduces with the increase in dopant concentration. All samples have magnetic hysteresis loops with diamagnetic background effects, according to VSM tests. A prominent and influential peak at 485nm in the PL spectra suggests that ZrO2 nanoparticles emit blue light. The produced nanoparticles were utilized as a photocatalyst to degrade Methylene Blue (MB) dye, and the results indicate that a high dopant concentration (0.08wt percent) outperforms pure and other dopant concentrations. Copper-doped ZrO2 has moderate anti-bacterial and anti-fungal activities.
Sarathi R; Meenakshi Sundar S
Abstract
Titanium-di-oxide nanoparticles are synthesized via a microwave-assisted solvothermal route for different pH values. The effect of the acidic and basic nature of the solvent due to the pH value is reflected in the crystalline size of the compound. The purpose of this work is to synthesize Titanium dioxide ...
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Titanium-di-oxide nanoparticles are synthesized via a microwave-assisted solvothermal route for different pH values. The effect of the acidic and basic nature of the solvent due to the pH value is reflected in the crystalline size of the compound. The purpose of this work is to synthesize Titanium dioxide nanoparticles and to observe their application in degrading industrially contaminated water using normal tap water. The crystalline sizes are calculated using XRD analysis and confirmed with HRTEM. The chemical composition and oxidation state are confirmed with XPS studies. Optical properties are carried out with UV-Vis, FTIR, and PL spectra. Photocatalytic studies are carried out to degrade the dye in industrial water. The efficiency of degradation is calculated with the UV-Vis data and formula. The reduction in band gap and high permanence has greatly supported in making it acceptable for photocatalytic activity under visible light. Dependence of time, initial dye concentration, and pH of the dye solution on TiO2 as a catalyst is investigated under the illumination of a visible lamp, and degradation efficiency to the highest of 96.79% has been obtained.
Sheik Mohideen Badhusha M; Kavitha Balasubramani; Rajarajan M; Tharmaraj P; Suganthi Ayyadurai
Abstract
ZnO, single-doped (Co-ZnO, Cu-ZnO), and co-doped ZnO ((Co, Cu)/ZnO) were effectively synthesized by the citrate gel combustion technique. The samples were characterized by UV-visible diffuse reflectance spectroscopy (UV-vis-DRS), Fourier transforms infrared spectroscopy (FT-IR), X-ray powder diffraction ...
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ZnO, single-doped (Co-ZnO, Cu-ZnO), and co-doped ZnO ((Co, Cu)/ZnO) were effectively synthesized by the citrate gel combustion technique. The samples were characterized by UV-visible diffuse reflectance spectroscopy (UV-vis-DRS), Fourier transforms infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and photoluminescence spectroscopy (PL). The average particle size was 30.33 nm as calculated from XRD patterns for (Co, Cu)/ZnO. UV-Vis absorption spectrum indicates that the co-doped ZnO exhibits increased visible light absorption compared to the undoped one. The photoluminescence spectroscopy shows that the separation efficiency of photo-induced electrons and hole is enhanced by the co-doping strategy. (Co, Cu)/ZnO nanoparticles demonstrated a strong visible light response and high photocatalytic activity for Rhodamine B (RhB) degradation under irradiation by visible light (400-500 nm). The visible-light photocatalytic activity of the prepared (Co, Cu)/ZnO may come about because of the incorporation of Co, Cu atoms in ZnO, photo-induced electron-hole pairs and extended the spectral response to the visible region. The antibacterial and antifungal activities of ZnO, Co-ZnO, Cu-ZnO, and (Co, Cu)/ZnO were studied respectively with Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative) ( bacterial strain) and Aspergillus flavus, Candida albicans (fungal strain). The (Co, Cu)/ZnO enhanced the antimicrobial activity.
Manmeet Kaur; Dixit Prasher; Ranjana Sharma
Abstract
The presence of various hazardous toxins such as Phenols, phthalates, pesticides, dyes, heavy metals, pharmaceutical waste, etc, is continuously increasing into the water bodies from different agricultural, industrial and domestic practices, which have brought the toxicity level to an alarming height. ...
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The presence of various hazardous toxins such as Phenols, phthalates, pesticides, dyes, heavy metals, pharmaceutical waste, etc, is continuously increasing into the water bodies from different agricultural, industrial and domestic practices, which have brought the toxicity level to an alarming height. Often, these toxic compounds are quite stable in nature and the removal or degradation of these compounds is quite challenging, which further poses a significant threat to the environment. When it comes to enhance the efficiency of water purification and decontamination process, SnO2 nanoparticles offer great potential owing to their low concentration and large surface area. Over the past few years, SnO2 nanoparticles as a photocatalyst has garnered huge interest from the researcher community towards the photo-degradation of toxic pollutants present in the water bodies. Among various metal oxides, particularly SnO2 has been emerged as the most versatile material for doping of different transition metals due to its plethora of applications such as photocatalysis, energy harnessing, sensors, solar cells and optoelectronic devices. The pure and doped SnO2 has prominent significance due to its phenomenal catalytic and physicochemical properties such as chemically stable, inexpensive and non-toxic. This review explores and summarizes the progress of first and second transition metal series doping in SnO2 for its coherent application towards the degradation of water pollutants. We have emphasized the effect of different transition metal dopants used in the growth of SnO2 nanoparticles on the basis of their synthesis technique, source of irradiation used, nature of contaminations removed and obtained photodegradation efficiency.
Dhanraj S Shirsath
Abstract
Magnetic nano adsorbent is cost-effective and easily synthesized in the laboratory by chemical Co-precipitation method that provides not only high adsorption capacity but also rapid adsorption rate. The magnetic nano adsorbents were synthesized by Ferric and Ferrous ions precursor solution in the presence ...
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Magnetic nano adsorbent is cost-effective and easily synthesized in the laboratory by chemical Co-precipitation method that provides not only high adsorption capacity but also rapid adsorption rate. The magnetic nano adsorbents were synthesized by Ferric and Ferrous ions precursor solution in the presence of ammonium hydroxide. In the present investigation, a magnetic nano adsorbent has been employed for the removal of Pb (II) from an aqueous solution by batch adsorption technique along with photocatalysis. The different parametric study also carried out such as initial concentration of Pb (II), adsorbent dose, contact time, and Solution pH. The Pb (II) was fast adsorption and the equilibrium was achieved within 45 minutes. The amount Pb (II) adsorbed increases as the temperature increase. The optimal pH for Pb (II) was around 5.4 and for the removal of Pb (II) ions was up to 96.00%. The employed adsorbents were characterized by SEM, X-ray diffraction (XRD), Vibrating spinning magnetometer (VSM), and FTIR. The Kinetic of adsorption study was examined for the pseudo-first-order model and pseudo-second-order models. This Photocatalytic adsorption study obeys Pseudo second-order kinetic. The reusability and regeneration of magnetic nano adsorbents were studied and were recycled up to 87.00 %.
Aishwarya Singh; bhavani prasad nenavathu
Abstract
Mg(OH)2/CdS heteronanostructures have been successfully synthesized by a novel precipitation method and the synthesis involves three steps. The first step involves the synthesis of Mg (OH)2nanoparticles using homogeneous precipitation method. Then, surface-modifying agent citric acid was used to functionalise ...
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Mg(OH)2/CdS heteronanostructures have been successfully synthesized by a novel precipitation method and the synthesis involves three steps. The first step involves the synthesis of Mg (OH)2nanoparticles using homogeneous precipitation method. Then, surface-modifying agent citric acid was used to functionalise Mg (OH)2. Finally, the cadmium sulfide (CdS) shell was deposited on the surface modified Mg (OH)2by co-precipitation method. The Mg(OH)2/CdS heteronanostructures were characterized using X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy. DRS results showed blue shift of CdS band gap absorption with respect to bulk CdS. XPS results showed evidence for the binding energies of Mg(OH)2, Cd and S. The Mg (OH)2/CdS heteronanostructures was explored as catalyst for sunlight induced photocatalytic degradation of β- naphthol pollutant. The batch of 0.2 mg/ mL of Mg (OH)2/CdS heteronanostructures maintained at pH 8.5 showed maximum photodegradation efficiency (75 ± 2.1 %). Higher photocatalytic degradation efficiency for Mg(OH)2/CdS heteronanostructures could be due to incorporation of CdS and increased reactive oxygen species (ROS) generation. The reusability of the Mg (OH)2/CdS heteronanostructures was also tested, and they show stability for up to three cycles without loss of efficiency.
Buvaneswari K; Arunadevi R; Sashikala S; Kavipriya K
Abstract
Visible light active ZnWO4/ZrO2 nanocomposite was prepared via hydrothermal method. The nanocomposite was characterized by UV-visible diffuse reflectance spectroscopy (UV-vis-DRS), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning Electron microscopy (SEM), energy dispersive ...
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Visible light active ZnWO4/ZrO2 nanocomposite was prepared via hydrothermal method. The nanocomposite was characterized by UV-visible diffuse reflectance spectroscopy (UV-vis-DRS), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning Electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM) techniques. The XRD results showed that average particle size of ZrO2, ZnWO4 and ZnWO4/ZrO2 were found to be 29.20 nm, 23.78 nm and 20.14 nm respectively and the phase structure for ZrO2 and ZnWO4 in the composite was Rhombohedral and Monoclinic respectively. The UV–vis absorption spectra of the ZnWO4/ZrO2 nanocomposite noticeably shifted to the visible light region compared to that of the ZrO2. The prepared photocatalyst were composed of plate and spongy sphere with little agglomeration was seen from SEM result. The photocatalytic activities of the prepared nanocomposite was evaluated for the degradation of methyl orange (MO) under visible light irradiations. The effect of operational parameters such as initial dye concentration, pH, catalyst concentration and irradiation time have been investigated in detail. The photocatalytic degradation efficiency of ZnWO4/ZrO2, ZnWO4 and ZrO2 for 95%, 72% and 60 % respevtively. The high photocatalytic activity can be attributed to stronger absorption in the visible light region, a greater specific surface area, smaller crystal sizes, more surface OH groups, and to the effect of ZnWO4 doping, which resulted in a lower band gap energy.
Emelda Rayappan; Jayarajan Muthaian; Muthirulan Pandi3
Abstract
A simple chemical methodology has been adopted for the synthesis of zirconium (Zr) doped and un-doped cadmium selenide (CdSe) nanoparticles for the application towards photocatalytic degradation of indigo carmine (IC) dye under solar light irradiation. The as prepared Zr-CdSe (doped) and CdSe (un-doped) ...
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A simple chemical methodology has been adopted for the synthesis of zirconium (Zr) doped and un-doped cadmium selenide (CdSe) nanoparticles for the application towards photocatalytic degradation of indigo carmine (IC) dye under solar light irradiation. The as prepared Zr-CdSe (doped) and CdSe (un-doped) nanoparticles were characterized by ultraviolet visible spectroscopy (UV-vis), X-ray diffraction (XRD), Scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDAX) and Transmission electron microscopy (TEM) studies. The inclusion of Zr ion into the CdSe nanoparticles matrix was confirmed by SEM-EDAX and XRD studies. TEM studies confirm the zirconium ions are uniformly doped over the CdSe surface. The photocatalytic degradation performance of Zr doped and un-doped CdSe nanoparticles were examined for the degradation of IC dye under solar light irradiation. The experimental results showed that the Zr doped CdSe possessed greater photocatalytic activity in comparison to un-doped CdSe. Photodegradation process parameters such as the initial concentration of the dye, as well as the amount of catalyst and time were investigated. The photocatalytic degradation rate was favored by a high concentration of solution in respect to Langmuir–Hinshelwood model.
Subramanian Kanchana; Radhakrishnan Vijayalakshmi
Abstract
Photocatalysis mediated by metal nanoparticles is emerging as an effective method for removal of hazardous dye pollutants in natural aquatic bodies. Nanoparticles of Cu, Ni and Ag were synthesized by chemical method using PEG and PVP polymers as capping agents. Experimental photocatalyis was carried ...
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Photocatalysis mediated by metal nanoparticles is emerging as an effective method for removal of hazardous dye pollutants in natural aquatic bodies. Nanoparticles of Cu, Ni and Ag were synthesized by chemical method using PEG and PVP polymers as capping agents. Experimental photocatalyis was carried out in a one pot batch reactor using metal nanoparticle catalysts for degradation of crystal violet (CV), bromocresol green (BCG) and methylene blue (MB) in aqueous solution in the presence of NaBH4 reductant independently under solar and UV irradiations at 25oC. Metal nanoparticles caused the removal of BCG and CV in 90-120 min and MB in 30-60 min. Linear relationship between the irradiation time and the absorbance were recorded and the kinetic plots exhibited pseudo-first order kinetic. The trend of dye degradation among the nanoparticles based on the catalytic efficiency (c) and rate coefficient (k) values was Cu>Ag>Ni. Mineralization experiment indicated 94, 91 and 90% of TOC removal ratio (R) respectively for CV, MB and BCG dyes. Nanoparticles stabilized using PEG demonstrated better catalytic efficiency than those with PVP. Solar irradiation showed superior augmenting effect on the nanoparticle catalysts than the UV irradiation. The electron-hole pair mediated reduction mechanism was proposed as a basis for photocatalytic degradation of dyes.